1. Field of the Invention
The present invention generally relates to an inner-rotor motor and, more particularly, to an inner-rotor motor having a separating member.
2. Description of the Related Art
A conventional inner-rotor motor includes an outer metallic housing and several components arranged in the metallic housing, such as a stator iron core, a driving circuit and a bearing. In this arrangement, electricity may be conducted between the metallic housing and the components, leading to the generation of a leakage current in the conventional inner-rotor motor.
To overcome this problem, another conventional inner-rotor motor 9 is provided as shown in FIG. 1. The inner-rotor motor 9 includes a stator 91 and a separating member 92. The separating member 92 is made of a non-conductive, plastic material and is used to receive the stator 91. The separating member 92 may be coupled with a metallic housing 93 for insulating purposes, to prevent the generation of a leakage current between the stator 91 and the metallic housing 93. Such a conventional inner-rotor motor 9 can be seen in Taiwan Patent No. M297577.
The separating member 92 is in the form of a cylindrical wall. Therefore, the stator 91 must be fastened with the separating member 92 to prevent relative rotation therebetween. The stator 91 includes a first screwing portion 911, and the separating member 92 includes a second screwing portion 921 aligned with the first screwing portion 911. In this arrangement, the separating member 92 can be fastened to the stator 91 using a screw “S.” However, since the separating member 92 is coupled to the stator 91 by fastening, the assembly of the inner-rotor motor 9 is inconvenient. Additionally, a single pair of the first and second screwing portions 911 and 912 may not be sufficient to provide a secure engagement between the separating member 92 and the stator 91. Thus, two or more pairs of the first and second screwing portions 911 and 912 are needed to fasten the separating member 92 to the stator 91 in a secure manner via the use of multiple screws “S.” Disadvantageously, the assembly of the inner-rotor motor 9 is even more inconvenient.
Furthermore, the separating member 92 is fastened to the metallic housing 93 using the same screw “S.” Since the separating member 92 is in the form of the cylindrical wall, the screw “S” must be arranged outwards of an outer surface of the separating member 92 to fasten the separating member 92 and the metallic housing 93 to each other. A radial length of the inner-rotor 9 motor is thus increased by the screw “S” arranged outwards of the outer surface of the separating member 92. Namely, when the separating member 92 is in the form of the cylindrical wall, arrangement of the screw “S” will certainly increase the volume of the inner-rotor motor 9.
Moreover, since a circuit or a coil inside the stator 91 has to be electrically connected to power or an actuator outside the inner-rotor motor 9 via a conducting wire, it is necessary to maintain a space between the separating member 92 and the metallic housing 93 for the conducting wire to extend through. However, arrangement of the space between the separating member 92 and the metallic housing 93 may further increase the volume of the inner-rotor motor 9.
In light of the above, it is necessary to improve the inner-rotor motor 9 to solve the problems of inconvenient assembly and large volume occupation.